Air Purifier VS Humidifier VS Dehumidifier

Air Purifier VS Humidifier VS Dehumidifier: What’s The Differences

If you have been shopping for air purifiers, you will probably notice usually there are 3 types of humidifier/ dehumidifier in the market: The air purifier humidifier, the stand-alone humidifier and the stand-alone dehumidifier. So what is the difference between the humidifier and dehumidifier? Should you get an air purifier with humidifier or just a stand-alone humidifier?

Short answer

Air purifier purify air. Humidifier increase humidity level. Dehumidifier decrease humidity level.

Long answer


Air Purifier VS Humidifier

Air Purifier


Varies that highly dependent on the airflow performance and features of the air purifier.Most mist humidifier is compact as oppose to the heavy-duty, 2-in-1 air purifier humidifier combo.
Circulates air through its filter to trap airborne allergens like dust mites, mold, pollen, pet dander, germs, bacteria, smoke and odor.Release cool or warm mist to help humidify the air in a room ideally between 30% – 50%.
Health Benefits
Stop airborne contaminants from spreading and aggravating health conditions like Sinusitis, Pulmonary Edema, Asthma, or other respiratory issues.Reduce dryness in skin, nose, moisture nasal airways and relieve discomfort from dry cough, dehydration. Also reduce static electricity.
Does not affect the room humidity level.Increase room humidity level.
Best Used
Bedroom, Living hall, Kitchen or places with poor air qualityBedroom, Living hall or places where the air is particularly dry especially during winter.
• Mechanical (HEPA)  • Activated carbon/ Deodorizer  • UV-light/ Ultraviolet  • PCO cleaner  • Ionic/ Ionizer  • Electrostatic  • Ozone generator• Evaporative  • Steam vaporizer/ Mist  • Ultrasonic  • Impeller
Target Group
With the exception of Ozone generator, air purifier is suitable for all age group specially for allergic person and asthma sufferer.For all age group but children must beware of the danger of warm-mist humidifier that can cause burns if gets too close.
Noise level
Varies based on airflow output and fan speed the air purifier is in. In general, the more powerful and higher the fan speed is, the louder background noise will be generated.Subtle for ultrasonic, cool mist humidifier while higher but liveable white noise for impeller, warm mist (steam) humidifier.
Cost with Upkeeping
For compact air purifier, price start from $20 – $150. Beyond that you will find higher output air purifier with large room size air purifier accountable for the higher price section.Most vaporizer/ cool mist humidifier would only cost between $20 – $50 while larger volume home humidifier or air purifier humidifier combo would cost in the range of $100 – $500.

The Difference between Air Purifier and Humidifier

Difference between air purifier and humidifier is not as huge as one would think. Yes air purifier has an overall bigger dimension to fit in its multi-layer filtration, there are still many identical size models notably in either air purifier and humidifier compact/ portable category. You could hardly tell them apart other than one carries a reservoir. Both air purifier and humidifier will alleviate or relieve common irritations like headache, cough, running nose, sore throat and flaky skin through different channel. Air purifier targets airborne particles and allergens via air circulation VS humidifier release moisture into the air that will increase the humidity level of a room. Moving into usability, you can literally use air purifier or humidifier at any corner of the room but we highly recommend placing it in bedroom or living hall where you will likely spend the most time in. Anyone can benefit from air purifier and humidifier but children, asthmatic, allergenic person would probably reap the most. Just make sure children are kept out from fiddling as the air purifier or humidifier may tumble, break or cause mild burn. Noise wise air purifier is distinctly louder even though the comparison is apples to oranges. Finally and perhaps most importantly for some, the cost of ownership. Air purifier in general is much more expensive to own or maintain with its quarter or annual filter replacement than humidifier one-off cost excluding any optional fancy essential oil addon. Maintaining air purifier is much easier as it does not require frequent water refill other than the occasion cleaning. In short, the main differences in air purifier VS humidifier is one purifies your breathing space and one increase the room humidity.


Air Purifier VS Dehumidifier

Air Purifier


Varies from compact to small, medium and large-sized air purifier.Slightly bigger to large body framework capable of fitting in its water tank.
Circulates air and trap airborne irritants like dust, mold, pollen, pet dander, bacteria, smoke and odor via its filter.Reduce humidity while at the same time stop mold and other microorganisms from growth by drawing moisture in the air.
Health Benefits
Stop airborne contaminants from spreading and aggravating health conditions like Sinusitis, Pulmonary Edema, Asthma, or other respiratory issues.Alleviate running nose, cough, headache and prevent respiratory and breathing problems that is likely associated with mold illness.
Does not affect the room humidity level.Decrease room humidity level.
Best Used
Bedroom, Living hall, Kitchen or unventilated places with poor air quality.Basement, Living hall or bedroom where high dampness and musty smell is an issue.
•  Mechanical (HEPA) •  Activated carbon/ Deodorizer •  UV-light/ Ultraviolet •  PCO cleaner •  Ionic/ Ionizer •  Electrostatic •  Ozone generator•  Mechanical or refrigeration • Absorption/ Electronic desiccant •  Thermoelectric •  Ionic membrane
Target Group
Other than ozone generator, air purifier can be used by all age group particularly you are suffering from asthma.Suitable for all with added value for people that is hyper-allergic to mold and other type of fungus.
Noise level
Highly dependent on the internal motor and airflow delivery rate, most air purifier generate little noise at low fan speed and loud noise at max speed.Like air purifier, dehumidifier noise level is determined by the moisture output but generally is slight louder than air purifier.
Cost with Upkeeping
Small size “compact” air purifier start from $20 – $150. Moving up the chain expect medium-sized air purifier priced between $200 – $400. Anything above that would likely land you a large-sized air purifier. Price start from $30 – $50 for the “mini” version and gradually move up for higher pint capacity, self standing dehumidifier price between $100 – $300.

The Difference between Air Purifier and Dehumidifier

Even though this should be a battle between air purifier VS dehumidifier, let’s first get the similarities out of the way. Both air purifier and dehumidifier come in all sizes occupying portable, small, medium to full console category. Anyone from baby, children, adult can truly enjoy the full benefits of dehumidifier and air purifier with the exception of ozone generator (bad for you, bad for all). Same story with background noise, the types, selected speed along with airflow distribution plays a major role in dehumidifier and air purifier output. Price point is also very similar at lower-end category but the gap widens for higher-end models with air purifier calling higher shot because of the complexity filtration and added features. Finally, both air purifier and dehumidifier can mitigate pain and discomfort like cough, sneeze, headache or breathing problems that is often corelated by mold. As for the difference between air purifier and dehumidifier, air purifier works by circulating air that go through its internal filter to trap airborne irritants like dust, mold, pollen, smoke to the extent of germs, bacteria and viruses. On the other hand, dehumidifier works by sucking out moisture from the air to stop ground mold and other microbes that thrive on moisture from growth. A perfection combination with air purifier able to quickly resolve on-going issue and dehumidifier giving it a permanent fix. You can run air purifier and humidifier in same room and at all places but bedroom is very likely the place to be as we spent the most time in or for dehumidifier case, basement due to the poor ventilation that often lead to high dampness level. Maintenance wise, the difference between air purifier and dehumidifier is the later has a higher frequency rate because you have clear out the water in the water tank when it gets full before resuming operation. In summary, air purifier and dehumidifier will help improve our room air quality with each using a different methodology.


Humidifier VS Dehumidifier



Typically compact in size unless is the full-sized version or air purifier humidifier combination.Beside the renewable or portable version, most dehumidifer has medium to large body with a removable water tank.
Raise room humidify to an ideal 30% – 50% via the emission of cool or warm mist.Reduce room humidity that is over 50% by absorbing moisture in the air. Mold and other microbes would fail to thrive without sufficient moisture.
Health Benefits
Moisture skin, nasal passage airways while alleviate dry cough and throat irritation. Humidifier also indirectly help reduce static electricity.Prevent mold-related allergies and symptoms like sinus, running nose, cough, headache that in long-run would lead to serious respiratory issues.
Increase humidity level.Decrease humidity level.
Best Used
Places you spend the most time in like bedroom, living hall particularly during winter time where humidity is low.Basement, living hall or bedroom covered with musty smell particularly during summer time where humidity is low.
• Evaporative  • Steam vaporizer/ Mist  • Ultrasonic  • Impeller•  Mechanical or refrigeration • Absorption/ Electronic desiccant •  Thermoelectric •  Ionic membrane
Target Group
Suitable for all but folks with children need to be extra cautious on heat produced in warm-mist humidifier.Suitable for all from children, adult to elderly that would be at risk of mold infection.
Noise level
Subtle to soft for ultrasonic, cool mist humidifier while liveable white noise for impeller, warm mist (steam) humidifier.Louder but manageable noise level that can be curbed depending on the speed or placement.
Cost with Upkeeping
Cheap for a compact vaporizer/ cool mist humidifier between $20 – $50. Expect price starting from $100 all the way to $500 for bigger models or air purifier humidifier combo.Mini/ portable dehumidifier is starting at an affordable price from $30 – $50. Expect an estimated price between $100 – $300 for a full-sized 30 – 70 pint dehumidifier.

The Difference between Humidifier and Dehumidifier

In ideal situation, humidity in a room would fall between the recommended 30% to 50%. In real-life, humidity is a climate variable that is affected by weather (heatwave/ rainfall), season (summer/ winter), location (basement/ air condition) and human factors (poor ventilation/ deforestation). Change is possible with many ways to go about it but let us focus on the use of home appliances i.e. humidifier and dehumidifier. While both machines are designed to help control the humidity level in a room, the big difference between humidifier and dehumidifier is the former add moisture into the air and the later reduce moisture from the air. In other words, humidifier would bring the humidity up through the release of cool or warm mist while dehumidifier would bring the humidity down by absorbing moisture from the air. Both humidifier and dehumidifier can create a more comfortable environment for person that is suffering from dryness, cough, sinus or nasal congestion; dehumidifier is better known for its contribution in stopping Toxic Black Mold and other microorganism from growth. With the right level of humidity, everyone from children, elderly to asthmatic patient would enjoy the full benefits of humidifier and dehumidifier. You can literally use both machines anywhere with humidifier popular for bedroom as it can keep skin hydrated while dehumidifier is often use in basement where high dampness along with musty smell roam. Noise level favors more to humidifier VS dehumidifier traditional refrigeration or desiccant mechanism. Lastly, the difference between humidifier and dehumidifier is the price point with humidifier is slightly cheaper but costlier to maintain. So to recap, humidifier would be used if the humidity level falls below 30 – 35% VS dehumidifier that is used if the humidity level is greater than 50%.


Air Purifier VS Humidifier VS Dehumidifier

Air Purifier



Small to Large Typically smallSmall to Large
Purify Air
Humidity Level
Not affected Increase Decrease
Variants (Types)
Quarterly to AnnuallyRegularlyRegularly
Noise Level
Soft to Loud Soft to AverageAverage to Loud
Cost including Upkeeping
Highest CheapestAverage

Leaf humidifier
Try not to get this humidifier that requires you to fill in unknown substances

When should you use a humidifier or dehumidifier?

If you have symptoms such as dry throat, flaky skin, sneezing and coughing especially just after waking up, chances are the humidity level in your room is way too low. Get a humidifier to increase the humidity level in your room. If you room its constantly infested with mold/ pollen/ dust mites, get a dehumidifier to reduce the humidity level and thus prevent mold from growing. Typically, children and people suffering from allergies such as asthma are more prone to this issue. High humidity level is the perfect environment for mold, pollen and dust mite to grow and flourish.

There are also the seasonal allergies that parents should be well-aware. In my country, we have a seasonal haze that will invade us in a yearly basis. During that period, majority of the air purifier/ humidifier would be sold off and there is limited room for price bargaining. So please be well prepare up front.

How About Air Purifier With built-in Humidifier? Yay or Nay?

I will strongly recommend getting an Air purifier with built-in humidifier unless you have a budget constraint. There is no difference between the two in terms of humidifying features. However, with an air purifier humidifier, it has the additional features of removing unwanted particles such as mold, pollen, dust, pet dander and even bad odor; humidifier can boost the effectiveness of the air purifier. Both would perfectly complement each other. By using air purifier with humidifier, it can run both simultaneously that not only will save you a bundle on purchasing one less unit, you will also save on your electricity bill due to the low energy consumption thus contribute to a greener mother nature. Best of all, since both air purifier and humidifier requires regular cleaning & maintenance, you would only have to keep track and maintain 1 unit. One downside though an air purifier humidifier will cost more than a stand-alone humidifier.

In summary,

  • Humidifier and dehumidifier serve the opposite functions. Humidifier increase moisture into the air and dehumidifier decrease moisture from the air.
  • If the room humidity level is below 30%, get a humidifier, above 50%, get a dehumidifier. The recommended level for humidity is between 30% to 50%
  • Generally, summer air = high humidity, winter air = low humidity
  • Most air purifier, humidifier/ dehumidifier comes with a humidity monitor built-in so an external humidity monitor is not necessarily
  • If you have “sick” symptoms e.g. dry skin, sinus, dry throat or asthma, get a humidifier
  • If you room is constantly infested with mold, pollen, dust mites, get a dehumidifier
  • If budget is not a main concern, consider an air purifier humidifier over a stand-alone humidifier.

And above all else, please note that both humidifier and dehumidifier can only play the part as the contributor. You will still need an air purifier to effectively clean your air. I hope by now you will have a good understanding on this, if not feel free to drop me a question on the comment section below.

10 thoughts on “Air Purifier VS Humidifier VS Dehumidifier: What’s The Differences”

  1. Hi. What is the best air purifier with humidifier.. That’s is most compact and good looking.. Doesn’t matter about price.. Just want one that’s good, pretty, compact, and easy to maintain.

  2. Thanks for the above.

    But I am confused you wrote “If you have “sick” symptoms e.g. dry skin, sinus, dry throat or asthma, get a humidifier”

    But then again above that you wrote ” If you room its constantly infested with mold/ pollen/ dust mites, get a dehumidifier to reduce the humidity level and thus prevent mold from growing. Typically, children and people suffering from allergies such as asthma are more prone to this issue.”

    Which seen to be saying if those with asthma are affected by mold/ pollen/ dust mites, get a humidifier or a dehumidifier?

    1. Hi Ken,

      Just follow the simple rules, if the humidity level is below 30%, get a humidifier. Anything above 50%, get a dehumidifier. You will need an humidifier reader to check on the level.

  3. Hi Sir i would like to ask if this Hitachi EP -A3000 can help co’z i always sneeze every morning and my eyes is teary almost everyday,, im working in a ship and leaving in a cabin

    Thank you

  4. How about combination Air Conditioner with Air Purifier + Humidifier, is there a product for that combo?
    I live in tropic country and I have asthma. What do you suggest for me to used?

    1. Not that I’m aware of. Not sure if you need a humidifier in tropic country but I would recommend a stand-alone air purifier as you could leave the unit turn on for 24/7.

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